1. Field of the Invention
This invention relates in general to control of a die casting machine.
More specifically, this invention relates to controlling a die casting machine using data previously derived and stored corresponding to a metal mold of the die casting machine.
2 Description of Related Art
FIG. 6 (PRIOR ART) is a block diagram of a die casting machine system. The system includes a main controller 20 including a sequence controller (not shown in this figure), a process controller 90, and a die casting machine 10. Such a system may be used, for example, in aluminum die casting. The sequence controller could be implemented using a micro-processors. In such a case, the micro-processor could directly control die casting machine 10. Main controller 20 manages various operations including the start of operation, various control timings during the die casting process and the like. Process controller 90 monitors the process status of die casting machine 10. For example, it may monitor such parameters as injection speed of molten metal, speed of an injection plunger (this may include a low speed injection process and/or a high speed injection process), pressure of molten metal, pressure during an intensification process or in holding pressure process, temperature of a metal mold, etc.
Process controller 90, may also be implemented using a micro-processor and could directly output signals indicating status. These signals are called, "injection cycle signal", "intensification signal" and the like. In such cases main controller 20 may not be able to detect the true status of die casting machine 10. Thus, main controller 20 and process controller 90 may share certain functions with each other.
To manufacture different products, the metal molds used in the die casting machine are changed (each product manufactured has its own unique metal mold). The die casting operation may have different parameters for each product manufactured. For example, plunger speed may be faster for product A than for product B. Thus, for each product manufactured, there is a unique set of data corresponding to the various parameters under which die casting should take place. Various parameters that may be changed, from product to product include, but are not limited to the following: injection speed, injection pressure, temperature of metal mold, pressure of molten metal, time period of processes and the like.
In known die casting arrangements, main control equipment does not automatically have the data defining the various parameters of die casting operation. An operator of the die casting machine must set the data each time a new product is to be manufactured. Thus, it is rather inconvenient and inefficient to change metal molds and begin to produce a new product.
There may be some situations in which the appropriate data are already set in the main control equipment for sequence control, however, such situations are rare. Typically, when changing from one mold to another, much time and effort must be expended to set the data appropriate for die casting with the new mold.
Thus, it is desirable to provide an arrangement that would output data appropriate to a particular mold or set of molds, which data could automatically be utilized in controlling a die casting operation.